Simplicity is great, as iOS has shown. But there’s a difference between conceptual simplicity and visual simplicity. Just hiding controls does make things appear simpler, but it doesn’t actually make them any simpler. The complexity is now just hidden. Similarly, removing features that few people use is a good idea, but like any good idea, it can be taken too far. At a certain point, you’re just making your application worse for everyone, even new users.
You can’t always tweak or refactor an existing application into the beautiful thing you’re envisioning. Sometimes the only way to achieve true simplicity is to start over with a new concept for the whole app.
That sums it up well. Just because software does complicated stuff doesn't mean it needs to look complicated or should be hard to use.
(via John Gruber)